Updated 13 October 2026 · SG Drone Inspections
Where the Drone Fits in a PFI
A Periodic Facade Inspection has two stages. Stage 1 is a visual inspection of the entire facade; Stage 2 is a close-up inspection of part of each face, including hands-on checks. Stage 1 is where drones make the biggest difference: instead of rigging gondolas or ropes down every drop of every elevation, a drone captures the whole facade in close-range, high-resolution images while everyone stays on the ground.
The Competent Person (CP) remains in charge throughout. The drone survey gives the CP a complete, consistent record to review — and a clear map of where Stage 2 close-up checks should go.
Two Ways to Work With Us
Capture for your CP
You already have a Competent Person or facade inspection firm. We plan and fly the drone survey to their requirements, handle the CAAS permits, and deliver the images and defect map for their review.
End-to-end PFI
You need the whole inspection done. We arrange a certified CP from our partner network and run the PFI from appointment to BCA submission. See end-to-end PFI.
BCA’s Rules for Drone Facade Inspection
BCA allows unmanned aircraft systems (UAS) to be used in a PFI under its technical reference TR 78 and its 2025 circular on UAS facade inspection. In practice that means:
- The CP notifies BCA before the drone inspection takes place.
- The CP is physically present during the flights and personally reviews all the images.
- Image resolution of 0.15 cm per pixel or finer, supplied as .jpg or .png without annotation.
- Provider approval — where the UAS provider is not accredited under the SAC scheme for facade inspection using UAS, written approval is obtained for the job.
- CAAS permits for the flights, with stricter conditions near aerodromes and in restricted airspace.
- Privacy — occupants are told in advance, and images are handled and stored under controls set out in TR 78.
Meeting the 0.15 cm/pixel Image Specification
Resolution on the facade — the ground sample distance, or GSD — depends on the camera’s sensor, the lens focal length and the distance between the drone and the wall:
GSD = (sensor width × distance) ÷ (focal length × image width in pixels)
We work this out for the camera and lens before each job to set the maximum stand-off distance that still achieves 0.15 cm per pixel, then plan each elevation as a grid of overlapping images at or inside that distance. Every image is logged to its elevation and position, so a defect seen in an image can be found again on the building. A telephoto lens lets the drone hold the required resolution from a safer distance on tall or congested facades.
How a Drone Facade Survey Runs
Site and airspace assessment
We check the site against CAAS airspace restrictions and proximity to aerodromes, and walk the site for take-off areas, obstructions, wind effects between towers and public access that needs cordoning.
Permits and notices
CAAS permit applications are made for the site, the CP notifies BCA, and residents or tenants receive advance notice of flight dates and privacy arrangements.
Capture with the CP on site
Each elevation is flown in a systematic pattern at the planned stand-off distance, with the CP present. Areas the CP wants to look at more closely can be re-flown on the day.
Image record and defect mapping
The full set of unannotated images is delivered for the CP’s review, together with a separate defect map that locates potential defects on each elevation by type.
Targeting Stage 2
The defect map helps the CP choose where close-up checks are needed, so access for Stage 2 is planned around actual findings.
What a Drone Can and Can’t See
| Visible in a drone survey | Needs close-up, hands-on checks |
|---|---|
| Cracks in render, concrete and tiles | Hollow or debonded tiles and render (found by tapping) |
| Spalling and exposed reinforcement | Tightness and condition of concealed fixings |
| Missing, displaced or bulging tiles and panels | Corrosion hidden behind cladding |
| Failed or missing sealant, gaps at joints | Testing of sealant adhesion |
| Rust staining, water staining, corroded brackets and grilles | Physical loading checks on fixtures |
Where moisture or debonding behind the surface is a concern, a thermal survey can add information, though it does not replace tapping.
Drone, Gondola or Rope Access for Stage 1?
| Drone | Gondola / BMU | Rope access | |
|---|---|---|---|
| Whole-facade coverage | Every elevation, including areas without anchor points | Limited to where the gondola can travel | Every drop must be rigged |
| Work at height | None | Yes | Yes |
| Site time | Shortest | Longer | Longest |
| Record for next cycle | Complete, positioned image set | Partial photos | Partial photos |
| Hands-on checks | No | Yes | Yes |
For a full comparison of access methods, see drone vs rope access for facade inspection.
What You Receive
- Full set of unannotated facade images meeting BCA’s resolution requirement
- Image index tying every image to its elevation and position
- Defect map by elevation, with defect type and location
- Flight records and permit references for the CP’s file
- Recommended locations for Stage 2 close-up checks
Frequently Asked Questions
Plan Your Drone Facade Survey
Tell us the building address, height and whether you already have a Competent Person. We will confirm airspace, permits and schedule, and send a fixed quote.